Using plate heat exchanger (PHE) for totally enclosed air-to-air cooled (TEAAC) motor

Traditionally, totally enclosed air-to-air cooled (TEAAC) motors have used tubular heat exchangers as means to dissipate internal heat. Today, many tubular heat exchangers used in TEAAC are optimized to achieve high heat transfer rates but are ultimately limited by the air flow configuration inside the motor that uses one part counter flow and one part parallel flow. This leads to poor heat exchanger efficiency and significantly uneven temperature difference between the drive end (DE) and non-drive end (NDE) of the motor. A comparison test has been made between traditional tubular TEAAC and a plate heat exchanger (PHE) with a symmetric internal flow configuration. Unlike the asymmetric cooling of the tubular heat exchanger, the symmetric flow along with the two-step cross flow used in PHE provides an efficient and uniform cooling on DE and NDE. Until now, PHE has been largely used in heat recovery for heating ventilation and air conditioning (HVAC) and closed-circuit cooling in applications such as telecom cabinets and wind turbine generators. It offers a tremendous weight and size advantage due to its compactness. However, PHE may not be suitable for every application due to certain limitations of the technology. The paper will discuss the design, test comparison and the feasibility of this technology in motor applications.